Cofferdam



March 13, 1934. E CAHILL 1,951,293

COFFERDAM Filed June 10, 1929 4 Sheets-Sheet 1 13 i 23 -21 21* 22% 24 Il l I I I I I l I I I I l l l l I l l I l I 11 6 J 17': J6

I "e I I? I I :/17 I 101-75 I I J2 11 I 21 I 222 I l I l I I I I I I \II I I l I I I I I I I I 'E QWW Janmsli. (kL/Ld/ COFFERDAM Filed June 10,1929 4 Sheets-Sheet 2 March 13,

J. E. CAHILL 1,951,293

' COFFERDAM Filed June 10, 1929 4 Sheets-Sheet 3 fTW 15 3521077267 3\E/MSlZ. UM ww M4 with reinforcing stiffening members of improvedPatented Mar. 13, 1934 UNETEE STATES FATENT GFFIE 17 Claims.

This invention relates to improvements in coffer-dams and its purpose isto provide a structure capable of being efiiciently, conveniently andsafely used in forming an inclosure from which the water. may be pumpedto form a chamber in which workmen may carry on various excavating orbuilding operations. The types of coffer-dams heretofore in use havebeen disadvantageous in that, to enable the structure to withstand thepressure of the water partially or wholly surrounding the coffer-dam, ithas been necessary to employ interior bracing and truss work which hasoccupied the space within the cofier-dam to such an extent as tointerfere with the operations of the workmen being carried on therein.The principal object of the present invention is to provide an improvedcoder-dam in which the use of interior bracing or truss work iseliminated. A further object is to provide a coffer-dam having anenclosing wall formed of interlocking piling in combination withreinforcing external truss work located preferably above the water line.Another object of the invention is to provide a coffer-dam comprising anenclosing wall made up of interlocking sheet piling in combinationconstruction and closure members adapted to form pockets which may befilled with mud or the like to insure a more perfect watertight closure.Still another object of the invention is to provide a coffer damcomprising a wall made up of a series of interlocking sheet piles ofarchshape in cross section having improved stiffening and reinforcingmeans attached to alternate interlocking piles. Otherobjects of theinvention relate to various features of construction and arrangementwhich will appear more fully hereinafter.

The nature of the invention will be understood from the followingspecification taken with the accompanying drawings in which oneembodiment is illustrated. In the drawings,

Fig. 1 shows a somewhat diagrammatic top plan view of a coder-dam madeup according to the principles of the present invention for use inconnection with the building of a bridge abutment, for example;

Fig. 2 is an enlarged detail section taken on the line 2-2 of Fig. 1;

Fig. 3 shows an enlarged partial plan View of a portion of the enclosingwall illustrating the reinforcement of alternate sheet metal pilesembodied therein;

Fig. 4 shows a top plan view of one side portion of the Coffer-dam, withparts thereof broken away, to illustrate the means for supporting thetruss structure and the working platform carried by the truss structure;

Fig. 5 shows a transverse vertical section on the line 5-5 of Fig. 4;

Fig. 6 shows an enlarged partial plan view of a coffer-dam wallcomprising an intermediate wall formed of sheet piling and havingreinforcing members extending in both directions from the sheet pilingwith closure members between adjacent reinforcing members and both sidesof the sheet piling, and

Fig. 7 is a partial top plan view of a modified form of construction inwhich I-beams and angle plates are attached to all of the sheet pilesforming the enclosing wall with closure members mounted between adjacentI-beams to form pockets.

In the accompanying drawings, the cofferdarn 10 is shown forming anenclosure 11 in which there is to be built a bridge abutment 12 havingthe outline indicated, leaving an unwatered working space around theproposed abutment and within the confining wall of the cofferdam. Thiscotter-dam may be located on the bank of a river, for example, having ashore line along the line 13, as indicated, so: that a portion of thecoffer-dam projects out into the stream. The chamber 11 is enclosed by adouble enclosing wall 14 comprising an inner wall 15 and an outer wall16 which are connected by a transverse portion 1'7 forming a series ofvertical pockets 18 adaptedto be filledwith mud or the like for furtherinsuring a water-tight closure. One or both of the walls 15 and 16 ismade up of sheet piling driven into the bed of the stream and into thebank and the sheeting of one wall preferably consists of interlockingsheet piling, of well known form, having interlocking members along thejoints to form a substantially watertight connection. In order to givestrength to the structure without the necessity of employing any bracingor reinforecements within the chamber 11, the enclosing wall 14 isprovided with one or more reinforcing truss structures 20 each of whichextends around the outside of the wall 14, preferably above the waterline, one such structure being shown in the drawings. This truss struc--ture 20 is made up of a plurality of outwardly extending braces 21extending normally to the wall of the coffer-dam and these braces areunited at their outer ends by the horizontal members 22 and at theirinner ends by horizontal mem-- bers 22*. A diagonal brace 23 ispreferably positioned in each of the rectangular openings formed by apair of the members 21 with one of the members 22 and a portion of thewall of the Coffer-dam, the braces 23 in adjacent openings beingdirected in opposite directions, as shown at the ends of the Coffer-dam,or inclined in the same direction on opposite sides of an intermediatepoint, as shown at the front and rear sides of the cotter-darn. Thistruss structure is preferably made up of steel members which are unitedwith each other and with the wall of the cofferdam in any suitable wayknown in the art. At the front corners of the confer-dam, on the riverside of the structure, the truss structure 20 pref erably comprisesdiagonal members 24 which connect the outwardly extending braces 21across the corner of the coffer-dam, thus connecting the trussstructures on adjacent walls.

The wall 14 of the cofier-dam is preferably made up in the mannerillustrated particularly in Fig. 3 where the inner wall section 15 isshown as comprising a plurality of interlocking sheet piles 25 of archshape in cross section, each pile having a web 25 connected at its endswith the curved portion 25 to which are attached the interlockingmembers made up of the hooked mem bers 25 and the curved guard members25. The locking members 25 and 25 extend vertically throughout thelength of the sheet piles 25 and they interlock with the correspondingmembers on adjacent piles in the manner illustrated in the drawings. Inthe particular embodiment illustrated, the piles are so arranged thatthe archshaped webs of alternate piles are directed inwardly while thoseof the intervening piles are directed outwardly. The webs 25 of thosesheet piles which are directed outwardly are reinforced by I-beams 26having their inner flanges 26 connected to the webs of the sheet pilesby fastenings 27, which may be bolts, rivets, welds or the like. Thesealternate sheet piles are further strengthened and reinforced by theinclined brace plates 28 which are united at one edge with the curvedportion 25 of the sheet piles by rivets 29. These inclined brace platesconverge toward the web 26 of the adjacent I-beam and. are attachedthereto by rivets 30 which also secure in place the angle plates 31.These angle plates are spaced inwardly from the outer flanges 26 of theI-beams, thus forming vertical guide-channels 32. These guide-channelsare adapted to receive the vertical plates or closure members 33, formedpreferably of wood, which extend between adjacent I-beams 26 and formthe outer wall 16 of the composite cotter-dam wall 14. It will beunderstood that the I-beams 26 and their cooperating parts constitutethe division and reinforcing Walls 17 illustrated in Fig. 1. There arethus formed between the inner and outer walls of the coffer-dam thepockets 18, each pocket being bounded on its inner side by the steelsheeting 25 and on its outer side by one of the closure mem bers 33. Theother two sides of each pocket are formed by two of the I-beams 26 whichare reinforced by the inclined brace plates 28. These pockets 18 arepreferably filled with mud or the like in order to insure asubstantially watertight closure for the interior chamber of thecoffer-dam. By reason of this reinforcement of alternate sheet piles,sufficient stiffness and rigidity is imparted to the enclosing wall 14to enable it to withstand the pressure of the surrounding water withoutthe use of any bracing structure on the inside of the wall and anynecessity for the use of such reinforcement on the inner side of theooffer-dam wall is further overcome by the use of the truss structure 20surrounding the upper portion or other desired portions of the wall 14.An assembled pile including an annular series of interlocking piles ofthe form described above is claimed in my cope-nding application, SerialNo. 356,009, filed April 18, 1929.

As illustrated in Figs. 4 and 5, the truss structure 20 is supported bya plurality of piles 35, preferably oak piles of round cross-section,which are driven into the bed of the river, and which terminate at theirupper ends at or adjacent to the water surface 36. These piles arepreferably arranged in two or more series extending parallel to thewalls of the coder-dam and spaced difierent distances outwardlytherefrom. Longitudinal wooden cap members 37 are supported on the upperends of the piles 35 of each series. Timber wales 38 are secured to thewalls 14 or parts thereof of the coffer-dam by bolts 39 and these timberwales serve with the cap members 37 to support the outwardly extendingtimbers 40. The timbers 40 are secured to the timber wales by bolts 41and are secured in place on the cap members 3'7 by drift bolts 42 whichextend downwardly through the timbers and through the cap members intothe upper ends of the piles 35.

The truss structure 20 is supported directly on the timbers 40 and theinner members 22* thereof are secured to the walls 14 of the cofier-damby bolts 43. The truss structure 20 is preferably made up of steelmembers 21, 22 and 23, having the arrangement shown diagrammatically inFig. i, and suitably united to each other at their meeting points. Aseries of Wooden stringers 44 are mounted on top of the truss structure20, being spaced apart outwardly from the parallel wall of thecofier-olam and being supported by the underlying members 21, 22, 22 and23 of the truss structure. An additional stringer 44 is preferablymounted on the outer side of each truss member 22, as shown in Fig. 5,and these stringers 44 and 44 serve as supports to which the woodenflooring 45 is secured by means of nails 46 or other fastening means.Each of the outer stringers 44 is preferably nailed or otherwise securedto the outer ends of the timbers 40 upon which it rests. In this waythere is provided a working floor extending continuously around thecotter-dam on its outer side and adjacent its upper edge so that theworkmen are enabled to move about the coffer-dam in carrying on theiroperations, without the necessity of obstructing the space within thewalls '14.

In many instances, particularly where the coifer-dam is comparativelydeep, it is desirable to use more than one truss structure surroundingthe coiTer-dam wall and in Fig. 5 such a truss structure is indicated indotted lines and. includes the timber wale 38 attached to the coffer-damwall, horizontal timbers 3'7 attached to the piles 35 and the outwardlyextending timbers 40 mounted on the timbers 37 and 38 In addition, thesetimbers may be reenforced by inclined bracing members, as described inconnection with the truss structure located adjacent the top of thecotter-dam.

In Fig. 6 of the drawings, there is illustrated a modified form ofconstruction comprising a series of interlocking sheet piles 50 formingan intermediate enclosing wall 51. The sheet piles 50 are channel-shapedin crosssection, comprising webs 50 connected by the curved parts 50with the interlocking members made up of the hooked members 50 and thecurved guard mem- =bers These sheet :piles are preferably ar rangedininterlocking relation with the channels .of adjacent :piles directedoppositely and all of the piles of the series are reenforced by I-beams'5 52 secured thereto by rivets 53 and provided :further with inclined'brace'plates 54 which are attached to the webs of the I-beams and tothe curved parts 50 of the-sheet piles, as in the constructionpreviously described. The I-beams 10 .and brace plates of adjacent sheetpiles are -di rected in opposite directions and each I-beam has angleplates 55 secured to opposite sides thereof to form channels 56 forreceiving the closure members 57, formed, preferably, of wood.

These closure members serve with the sheet piles and the reenforcedI-beams to form pockets 58 .located on both sides of the sheet pilingwall.

.The leakage of water into the space enclosed by the coffer-dam is thusprevented not only by the sheet piling wall and two outer enclosing.walls formed by the members 57 but also by two series of pockets whichmay be filled with mud or the like.

InEig. '7, there is illustrated a further modifi- 25 cation in which thesheet piles 60, forming the enclosing wall of the coffer-dam, areprovided with vI-beams 61 secured to each pile of the series anddirected outwardly in the same direction therefrom; .Brace plates 62connect the I-beams 61 with the curved end portions of the sheet pilesand angle plates 63 are secured to the webs of the I-beams to formchannels 64 between the flanges of these angle plates and the parallelflanges 61 of the I-beams. Closure members 65, formed preferably ofwood, are inserted in these guide channels 64, thus forming a series ofpockets 66 between the walls formed by the interlocking sheet piling andthe walls formed by the closure members 65. As in the constructionspreviously described, the pockets 66 are adapted to be filled with mudor the like for the purpose of preventing the leakage of water throughthe wall. Although one form of the invention has been shown anddescribed by way of illustration, it will be understood that it may beconstructed in various other embodiments within the scope of theappended claims.

I claim: 1. A cofier-dam comprising a continuous en- :55- closing wall,and a truss structure surrounding said enclosing wall and directlyoutwardly therefrom adjacent the upper part only thereof to preventinward collapse of said wall.

2. A Coffer-dam comprising a continuous dou- 55; ble enclosing wallforming an inner eenclosure, and a reenforcing truss structurecontinuously surrounding said double wall to prevent the inward collapsethereof.

3. A coffer-dam comprising a surrounding agadouble enclosingwall ofsheet material forming an inner enclosure, a truss structurecontinuously surrounding said enclosing wall and extending horizontallyoutward therefrom, and means for supporting said truss structure, thespace within as said enclosure being unobstructed.

" 4. A coiTer-dam comprising an enclosing wall, a truss structuresurrounding said enclosing wall and extending horizontally outwardtherefrom adjacent the upper part thereof leaving said enfjl, closureunobstructed, and means located on the outer side of said enclosing wallfor supporting said truss structure, whereby aid truss structureprevents inward collapse of said wall.

5. A coifer-dam comprising a double enclosing 1 wall forming an innerenclosure, a series of piles driven :outside of saidenclosureyandahorizontal truss structure connected to the upper part'of said enclosingwall andsupported by said piles :to prevent inward collapseof said-wall.

:6. A coffer-dam comprising a continuous enclosing "wall forming aninner enclosure, a series of piles driven outside of said enclosure,a-truss structure connected to said enclosing wall-around the outside ofsaid wall and supported by said piles-and a platform carried by saidtruss structure around said enclosing wall.

7. A coifer-dam comprising am enclosing wall of sheet piling forming anunobstructed enclosure, a series of piles driven outside of said wall,an outwardlywextending frame carried by said piles, a trussstructure'mounted on said frame and attached to said 'wall to preventthe inward collapse of said wall, a plurality of stringers mounted onsaid truss structure parallelto said wall, and flooring carried by saidstringers.

8. A coifer-dam comprising an'enclosing wall formed of a plurality ofinterlocking sheet piles of arch-shaped cross section having the archesof adjacent sheet piles directed in opposite direc tions, andreenforcing I-beams attached to the webs of alternate sheet piles, angleplates attached to said I-beams to form guideways in conjunction withthe fianages of said I-beama'and closure members extending betweenadjacent I-beams and engaging said guideways.

9. A coifer-dam comprising an enclosing wall formed of interlockingsheet piling, each pile being of arch-shaped cross-section, reenforcingmembers attached to the webs of said sheet piling and extendinglongitudinally thereof, and inclined brace plates attached to saidreenforcing members and to the arches of the connected sheet piles.

10. A coffer-dam comprising an enclosing wall made up of a series ofinterlocking sheet piles of .115 arch-shaped cross section arranagedwith the arches of adjacent piles directed oppositely, reenforcingmembers attached to the webs of alternate sheet piles and extendinglongitudinally thereof, and inclined brace plates attached to 120 saidreenforcing members and to the arches of the connected sheet piles.

11. A sheet pile comprising a member of archshaped cross section havinginterlocking members extending longitudinally of its lateral edges, 125a reenforcing member secured to the intermediate web of said sheet pileand extending therefrom, and inclined brace plates attached to the outerportions of said sheet pile and having their opposite convergingextremities secured to said 130 reenforcing member.

12. A sheet pile comprising a member of archshaped cross section havinginterlocking members along its edges, an I-beam attached to the web ofsaid sheet pile and extending longitudinally thereof, and inclined bracemembers attached to the web of said I-beam and having their outwardlyconverging edges attached to said sheet pile.

13. A coifer-dam comprising a continuous series 140 of sheet pilinginterlocking along their vertical edges to form an inner enclosure,vertical reenforcing means secured to said sheet piles on the outersides thereof, closure members extending between said beams to form withthe outer portions 14;, of said beams an outer enclosing wall, fillingmaterial inserted in the pockets between said first named enclosing walland said outer enclosing wall to provide a substantially water-tightclosure, and means located entirely on the outside of said 153 enclosingwalls for reenforcing them and preventing inward movement thereof.

wall to provide a substantially water-tight closure,

a horizontal truss structure connected to said outer enclosing walls andextending horizontally outward therefrom. continuously around saidwalls, said truss structure comprising outwardly extending and diagonalmembers adapted to prevent the inward collapse of said enclosing walls,and piles driven around the outside of said enclosing walls andconnected to the outer portion of said truss structure for supportingsaid truss structure.

15. A cofier-dam comprising a continuous series ofsheet pilinginterlocking along vertical edges to form an inner enclosure ofrectangular cross section having each of its walls aligned substantiallyin one plane, a truss structure located in a horizontal plane on theoutside of said enclosing walls and extending continuously around saidenclosure to prevent inward collapse thereof while leaving the spacewithin said enclosure unobstructed, and supporting pilings spacedoutwardly from said enclosure for supporting said truss structure.

16. A coiTer-dam comprising a continuous series of sheet pilinginterlocking along their vertical edges to form an inner enclosure ofrectangular cross section having each of its walls aligned substantiallyin one vertical plane, vertical reenforcing members secured to the outersides of said sheet piles and a plurality of guideways at their outeredges, closure members engaging the guideways of adjacent verticalreenforcing members to form an outer enclosing wall, a truss structureconnected to said sheet piling and extending outwardly therefrom in ahorizontal plane continuously around said enclosure, said trussstructure comprising outwardly extending and diagonal members securedtogether to prevent'the inward collapse of said enclosing walls, andpiles supporting the outer portion of said truss structure.

17. A coffer-dam comprising an enclosing wall of sheet material, andmeans for holding said wall against inward collapse, said meanscomprising a truss structure attached to the upper part of said wall andextending outwardly therefrom to leave the interior of said coffer-damunobstructed.

JAMES E. CAI-IILL.

